PNDS / Marking codes / A3

Identify an unknown SMD part: marking code “A3”

Packages rarely print the full part number. The marking below is shared by several part numbers — use the package, pin count and the manufacturer family together to narrow it down, then confirm against the datasheet.

25 candidates 25 with manufacturer source-traceable

Candidate part numbers

Part number	Manufacturer	Package	Mapping source
1N4448W	DIODES	SOD-123	Public marking directory
1N4448WS	FSC	SOD-323	Public marking directory
1PS300	NXP	SC-70	Public marking directory
1PS300	PHI	SC70	Public marking directory
1SS181	MCC	SC-59	Public marking directory
1SS181	MCC	SOT-23	Public marking directory
1SS300	TOS	SOT-323	Public marking directory
1SS306	TOS	SOT-143	Public marking directory
1SS360	TOS	SOT-23	Public marking directory
BAP64-03	PHI	SOD-323	Public marking directory
BAS16	FSC	SOT-23	Public marking directory
BAT17	NXP	SOT23	Public marking directory
BZX79-A2V7	PHI	SOD27 (DO35)	Public marking directory
HSMS-2803	HP	SOT-23	Public marking directory
MBT3906DW	MOT	SOT-363	Public marking directory
MC2832	MOT ^*	SC-59	Public marking directory
MMBD1005	MOT	SOT-23	Public marking directory
MMBD4448	FS	SOT-23	Public marking directory
MMBD4448HT	DIODES	SOT-523	Public marking directory
MMBD4448HTA	DIODES	—	Public marking directory
MMSZ12	ON ^*	SOD-123	Public marking directory
R3113D131A	RICOH ^*	—	Public marking directory
R3114Q101A	RICOH ^*	SC-82AB	Public marking directory
RT9161-33CX	RICHTEK	SOT-89	Public marking directory
TC1014-3.0VRX	MIC ^*	SOT-23-5	Public marking directory

How we narrow this down

Package first — SOT-23 vs SOD-123 vs SC-59 eliminates most candidates immediately.
Pin count and body size — a 3-pin SOT-23 LDO cannot be a 6-pin dual transistor.
Marking style — laser-marked parts are usually newer production; ink marking often indicates older or second-source vendors.
Circuits around it — a part sitting on a rail with an inductor is a regulator, not a diode.
Datasheet check — every credible candidate lists its marking scheme in the “marking information” section.

FAQ

Same code, several parts — which one do I actually have? Compare package + pin count + surrounding circuit; if it still fits two parts, request a sample verification before production.
Can I substitute between the candidates? No — the same marking may sit on electrically different parts. Always match the electrical spec sheet, not just the marking.
Where do these mappings come from? Public SMD marking directories and historical stock tables; each row keeps its source so you can trace it.

Other codes starting with “A”

AL AH-16 A1 A2 A4 A5 A6 A7 A8 A9

Still not sure what the part is?

Send the code, package and a photo through the BOM hub — our engineers cross-check it against datasheets and sourcing records.

How these mappings are compiled: public SMD marking directories plus our own stock records. Each row keeps its original reference internally, so any mapping can be traced on request. ^* Manufacturer derived from the part-number family (some directory entries carry no manufacturer) — treat it as a lead, not a datasheet fact. Markings are indicative only — confirm with the physical batch marking and the original datasheet before ordering.